Muscles of the Arm

Question 1

Biceps Brachii

Answer 1

O: short head- coracoid process of scapula; long head- supraglenoid tubercle of scapula

I: tuberosity of radius

A: supination of pronated forearm; flexion of supine forearm; flexion of arm

N: musculocutaneous n. (C5, C7)

Question 2

Brachialis

Answer 2

O: ant. surface of humerus

I: coronoid process of ulna

A: flexion of forearm in all positions; main flexor of the forearm

N: musculocutaneous n. (C5, C6)

Question 3

Coracobrachialis

Answer 3

O: coracoid process of scapula

I: medial surface of the humerus

A: helps with flexion and A44 of arm

N: musculocutaneous n. (C5, C6)

Question 4

Triceps Brachii

Answer 4

O: long head- infraglenoid process of scapula; lat head- post surface of humerus; med head- post. surface of humerus

I: olecranon of ulna and fascia of forearm

A: extension of forearm; chief extensor; long head steadies head of abducted humerus and assists in extension and a44;

N: radial n. (C6, C7, C8(

Question 5

Anconeus

Answer 5

O: lat. epicondyle of humerus

I: olecranon process and sup. part of post. surface of ulna

A: assists triceps in extending forearm

N: radial n. (C7, C8, T1)